Work will soon start on a purpose-built facility at Hi-Quality Group’s Sunbury Eco-Hub that will manage and dispose of soil excavated by the tunnel boring machines on the West Gate Tunnel Project.

Want to learn more? Check out some of our most frequently asked questions below.

What are the levels of PFAS expected in the soil that will be sent to Hi Quality?

Testing shows the levels of PFAS expected to be found during tunnel boring are low and at safe levels for the community and the environment.

Groundwater testing along the tunnel alignment shows PFAS levels of between zero and 0.7 micrograms per litre or less, which is between detectable limits and much less than water that is safe to swim in.

Why can’t the soil be tested before it gets to Sunbury?

The soil needs to be transported and tested at the Hi-Quality Eco-Hub because of the time needed to get soil test results.

At the Hi-Quality Eco-Hub the soil will be stored in specially engineered and lined containment bays until the test results come through, and then a further 7 days to dispose of the soil and prepare the bays for receipt of the next soil delivery.

What happens if soil with PFAS levels higher than what the site it approved to take are found?

Any soil with PFAS levels above EPA approved criteria must be disposed of to an EPA facility licensed to accept this waste.

Where the soil material is classified as category C contaminated soil, it will be disposed of in Hi-Quality’s existing Category C licenced cell within their EPA licence.

Where the soil is categorised as Category B it will disposed of, or treated, off-site at an EPA facility licensed to accept waste of that kind.

Who made this decision?

Transurban and its builder CPB John Holland Joint Venture are responsible for managing soil excavated as part of the project. Following its tender process, CPB John Holland Joint Venture recommended the Hi-Quality facility as the preferred site after an assessment of proposals from three sites.

To enable tunnelling to get underway as soon as possible, Transurban will advance funding so construction can commence at Hi Quality’s facility, which is expected to generate up to 200 additional jobs and take around six and a half months.

Why was Hi-Quality chosen as the preferred site particularly when there has been so much community opposition?

The Hi-Quality site was chosen as the preferred site by Transurban’s builder CPB John Holland Joint Venture following a comprehensive assessment of three potential sites as part of its tender.

Hi-Quality has decades of experience running landfill operations safely and responsibly.

The site already has existing licenses to accept soil with levels of PFAS in it in their existing Category C cells. Hi-Quality will be required to meet strict planning and environmental requirements to ensure the safe transportation, storage and containment of the soil and that the site operates in a way that minimises the impact on the surrounding community and environment.

The Minister for Planning considered the views of the community and of Hume City Council in his decision. Based on the review of Hi-Quality’s application, concerns raised by submitters and Council can be mitigated through conditions placed on the planning approval in conjunction with the requirements of the environmental management plan approved by the EPA.

What will happen with the unsuccessful sites at Bacchus Marsh and Ravenhall and a back-up site?

The Hi-Quality facility has been designed to manage and dispose of all of the tunnel soil excavated by the tunnel boring machines. There are no agreements in place with either Maddingley Brown Coal in Bacchus Marsh, Cleanaway in Ravenhall, or at Wyndham Vale to manage tunnel soil from the project.

Some people have complained that the Hi Quality site isn’t suitable to take this soil?

Hi-Quality is already an existing Category C waste facility and regularly accepts material of this type.

Hi-Quality, through the planning and environmental approvals, has shown they can manage the soil safely and responsibly, and to a standard that far exceeds what’s required for the likely low contamination levels of the soil – with minimal impact to the community and the environment.

Why can’t tunnel boring soil be disposed of at existing landfills?

The soil generated from tunnel boring can exceed the rate of waste acceptance of Victoria’s existing landfills and significantly reduce the future capacity of these landfills.

The West Gate Tunnel Project alone is due to create 1.5 million m3 of soil from the tunnel alignment over an 18-month period. Landfills in Victoria cannot absorb this volume of soil within an 18-month period, without exhausting existing capacity.

In addition, the tunnel soil will be wet and requires a large area to spread out to aid dewatering prior to deposit in a cell – the space and infrastructure is not available at most landfills. Most landfill cells have relatively small operating ‘tipping faces’ where wastes are placed.

Is contaminated soil from the West Gate Tunnel Project already being taken to the Hi-Quality site?

Hi-Quality has taken large volumes of waste material including non-contaminated and contaminated soil from major infrastructure projects since 2003. Under their existing licence, they have been taking some material from major infrastructure projects, including other parts of West Gate Tunnel Project.

Will Hi-Quality be the preferred site to collect soil for all major projects going forward?

Hi-Quality’s site is being purpose-built for the West Gate Tunnel Project. The site’s planning and environmental approvals also relate only to the West Gate Tunnel Project.

How will the site be built to ensure the safety of the community and environment?

The Hi-Quality site has been rigorously assessed to ensure all environmental issues are addressed.  This includes groundwater and surface water quality, air quality, and noise.

What will happen with the soil when it gets to the site?

The soil from the West Gate Tunnel Project will be transported in specially covered and sealed trucks to lined containment bays where it will be held for assessment and testing.

Hi-Quality will build a number of specially engineered and lined containment bays to protect ground water, surface water, and a drainage system to catch and collect water for treatment.

Once tested, the water will be drained off and treated through a water treatment plant at the Hi-Quality site, resulting in water that is within Australian Drinking Water Guideline levels.

The soil will then be classified and either contained on site in a purpose-built lined facility, disposed of to a licensed landfill or reused to support future developments or other projects.

What is being done to protect groundwater and surface water such as Emu Creek from contamination?

The holding bays and containment cell will be specially constructed with layers of impermeable lining. The water will be removed from the soil and then contained in lined pre-treatment leachate holding ponds, prior to being pumped to an onsite water treatment plant.

The water will then be treated to drinking water quality and potentially be re-used on-site for dust suppression or disposed to a licensed facility.

Managing the soil and the water this way ensures that there is no link to the groundwater system – except in the instance where the contaminants have been removed to at least drinking water standards.

Groundwater and surface water will also be monitored to ensure that no impact has occurred.

Are there any protected species in the area, and how will their safety be ensured?

The preliminary assessment of the site identified the presence of native vegetation and potential presence of, spiny rice flower and habitat for the golden sun moth and growling grass frog.

The detailed assessment of the site identified native vegetation which will be offset in accordance with the requirements of the Melbourne Strategic Assessment and Melbourne Strategic Assessment (Environmental Mitigation Levy) Act 2020.

The planning approvals include measures required to minimise the impact on significant flora and fauna and prevent the introduction and spread of pest plants, weeds and disease.

What is the haulage route and how many extra trucks will use Sunbury Road?

As part of its proposal, Hi-Quality was required to assess a number of potential haulage routes. A key focus in the consideration of truck haulage has been avoiding residential areas, house frontages and community facilities such as schools.

The traffic route assessments will support the development of a traffic management plan in consultation with the relevant road manager and to the satisfaction of the Head, Transport for Victoria, in the Department of Transport. This Plan will report on the specific controls to be implemented to manage truck traffic, including any findings from structural inspections, and any considerations relating to the final haulage route.

It is estimated that there will be between 86 and 429 trucks per day over the tunnel boring period, with approximately 229 truck per day average, and a peak of 429 per day over a very short period. (all figures are one-way volumes).

Sunbury Road, city-side of Bulla township currently carries 2,100 trucks a day. Sunbury side of Bulla township currently carries 1,400 trucks per day. In total Sunbury Road, city side of Bulla township, carries 24,000 vehicles per day and Sunbury Road Sunbury side of Bulla township carries 18,000 vehicles per day.

I’m worried about the increased number of trucks using Sunbury Road – what’s being done from a road safety and amenity perspective?

Hi-Quality must prepare a traffic management plan to the satisfaction of the Head, Transport for Victoria, which must include a road safety audit to ensure trucks from the project do not increase road safety risk.

Hi-Quality has proposed a number of changes to Sunbury Road at the access points to make it safer for traffic travelling on Sunbury Road while an increased amount of trucks are entering and exiting the site.

To keep dirt and mud off roads, all trucks transporting the soil will be sealed and covered for the entire journey. In addition, Hi-Quality will provide a wheel washing facility for all trucks before they exit the site onto Sunbury Road.

What will be done for the Sunbury Road heritage bridge?

As part of the approvals by the Minister for Planning, Hi-Quality is required to enter into a road maintenance agreement with the Department of Transport, with any additional road and infrastructure costs associated with soil disposal met by Hi-Quality.

Assessments have been conducted to demonstrate that the Deep Creek Bridge is capable of handling the number and load of trucks. Hi-Quality is also required to implement a structural inspection and maintenance regime for the Deep Creek Bridge for the duration of the project.

If any concerns arise during the monitoring of the historic bridge that affect its capacity to carry trucks, then Hi-Quality will need to seek approval for an alternative route, while ensuring there are no increased impacts to local communities.

When will Hi-Quality start building the site?

Hi-Quality has the necessary planning and environmental approvals to commence works. We expect that work will start soon.

How will noise be managed?

Noise criteria specific for the site and surrounding area are required to be adhered to.

During construction of the site, every effort will be made to reduce noise through measures such as minimising consecutive nights of construction noise, using quieter construction methods where feasible, schedule loading and unloading of material during daylight hours.

Hi-Quality will be in regular communication with residents in regard to planned works and noise generating activities.

During operation of the site Hi-Quality is required to ensure that any earth walls, enclosures and screening vegetation is maintained. In addition, a plan will be developed that details noise management procedures and there will be regular noise monitoring to ensure the noise criteria is being met.

Is there a risk to air quality because of the dust from the soil?

The soil generated from tunnel boring machines is expected to have only very low levels of PFAS. When the soil is brought to site, it will be wet when it arrives and when it is emptied into the containment bays. At this point, the excess water will start being removed from the material for treatment.  Due to the expected high moisture content of the soil, the potential for air blown dust is considered to be very low.

To ensure dust generation is kept to a minimum, Hi Quality will be required by EPA to implement dust suppression controls. Air quality monitoring will also be undertaken to assess that dust control methods are working and effective.

How do you know the Hi-Quality site is safe?

The site is purpose built for the job and is engineered to take a much higher level of contaminated soil than what is expected to be found.

Hi-Quality also has decades of experience in running landfill operations safely and responsibly. The site already has existing licenses to accept soil with levels of PFAS in it in their existing Category C cells.

When will tunnelling commence?

Hi-Quality will need to prepare its facilities to safely manage the rock and soil excavated by the tunnel boring machines before tunnelling can commence. This work is expected to take around six and a half months and is weather dependent.

What will happen to the site after it isn’t used anymore?

The site will be used only for the processing and disposal of West Gate Tunnel soil and it has a limited time planning approval. The planning control requires the remediation and rehabilitation of the site before the planning control expires.

The processing site will be rehabilitated and will be eventually developed in line with the Sunbury South Precinct Structure Plan. This plan provides for the development of the area for industrial and commercial development with an open space / stormwater retention area. The form of development will be guided by the precinct plan and planning permits granted by the Hume City Council.

The containment cell will be managed as provided for in the EPA approved Environmental Management Plan and the requirements of the Tunnel Boring Machine Regulations. Ongoing monitoring of groundwater and surface waters will be undertaken following completion of the project.

The processing and storage of excavated soil from the West Gate Tunnel Project will not cause any unacceptable impact or leave any detrimental environmental legacy either on site or in the local community. <